Compressibility and consolidation of unsaturated soils with high degree of saturation and its application

Unsaturated soils with high degree of saturation(Sr) are usually found in the gas-contained sediments of lakes and coasts as well as in the compacted soils with high water content.In this type of unsaturated soils,the air phase generally exists in the form of occluded bubbles within the pore water and moved with the pore water.It was assumed that the unsaturated soil with high Sr was a two-phase soil with a compressible fluid(i.e.,mixture of water and air bubbles).On the basis of this assumption,a formula was derived to calculate the soil compression under an un-drained condition,and then a close-form solution was developed to calculate the one-dimensional consolidation of the unsaturated soil.The obtained formula and solution were used to analyze the pore pressure parameter,the saturation processes(by applying back pressure and cell pressure) and the one-dimensional consolidation process,and compared with the saturated soils in detail.In addition,the main parameters affecting the compressibility and consolidation of this soil were analyzed.